Group selector



4Sept. 17, 1929. D. L. LIENZEN A A 1,728,349

GROUP SELECTOR Filed Dec. 28, 1,927 4 Sheets-Sheer, l

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Sept 17, l929- D. L. I IENZEN 1 ,7 28,349

GROUP SELECTOR Filed Deo. 28, 1927 4 Sheets-Sheet 2 /NVNT a SPfv 1-7, 1929-- D. 1 I IENZEN 1,728,349

' GROUP SELECTOR Filedbec. 28, 192'/ 4 Sheets-Sheet 3 NRM SCP- 17, 1929- D. 1 LxENzEN 1,728,349

GROUP SELECTOR Filed Dec. 28, 1927 4 Sheets-Sheet 4 IWW/0.

By.. 0MM/A fig Patented Sept. 17, 1929 UNITE@ STATES PATENT OFFICE DAVID LAURENTIUS LIENZN, OF STOCKHOLM; Svi/"EDEN, ASSGNOR TO TELEFON- AKTIEBOLAGET L. M. ERICSSON, 0F STOCKHOLLV, SWEDEN, A COMPANY OF SWEDEN GROUP Application led December 28,. 1927, Serial No. 243,127, and in Sweden January 5, 1927.

For the purpose of distributing uniformly the telephone traffic on the different junction lines of automatic telephone exchanges it has already been proposed to use pre-selectors or searchers of the kind which have no delinite normal position and which, therefore, are started each time from the position into which they have been previously set. Heretofore i has been impossible to provide for a similar mode of operation of group selectors generally such selectors must be set from a fixed initial position. To obtain a uniform distribution of the traffic over the junction lines leading from such selectors it was therefore necessary to make use of a special wiring of the contact fields of the selectors, so that the selecting of a disengaged junction line of a group of lines will take place in a different order of sequence in the different group selectors having access to the same line group. In some systems, however, such wiring of the contact fields can not be used with advantage. This is for instance the case in systems where the Contact field of the selectors consists of bare wires which form bundles of parallel wires extending through a plurality of selectors. The present invention has for its object to provide for a uniform distribution of the connections also in systems of this kind. For this purpose the group selectors are provided with a number of movable switching members corresponding to the different groups of lines and adapted to be set in known manner to select a particular line in the appertaining group the switching men bers belonging to different selectors but operating in the same group of lines being adapted to select the different lines of this group in a different order of sequence or from different initial positions respectively.

rllhe invention will be more closely described with reference to the accompanying drawings, in which Figures l to 3 show the invention as applied to selectors of the kind in which the incoming and outgoing lines extend through the contact field in diffe-rent directions perpendicular to each other and are connected at the points of intersection to contacts which can be selected and operated by means of a selector mechanism provided in front of the contact field.

The characteristic feature of such selectors is that they have no disolaceable contact arms. The invention is,

however, not limited to such selectors as it may be applied with advantage also to selectors having displaceable contact arms. Figure l is a section on the line 1 1 of Figure 2.

Figure 2 is a front view of a number of group-selectors and the appertaining contact field. section on the line 3 3 in Figure l.

Figure 3 is a horizontal Figures 4 to 9 are side views and plan views of different modifica tions of the switching member.

Figures 1G and 11 are a side view and a plan view respectively of a group-selector raving contact arms and provided with an auxiliary selector for the selection of the contact arms.

ln the construction shown in Figures l to 3 the wires of the Contact field as well as the selector mechanisms are mounted in a frame work consisting of a number of vertical beams l which are joined together at their upper and lower end by means of horizontal bars 2, 3. Between the two beams of each pair there is provided a number of for instance ten or fifteen identical selector mechanisms with appertaining contact fields.

The latsented by the vertical wires 5.

The wire iield is carried by aframe work arranged between the horizontal bars and consisting of two vertical zontal bars bars 6, 7 and a number of hori- 8 of an angular cross-section which are screwed to the bars 6, 7, and further a number of vertical bars 9 which are screwed to the horizontal bars 2, 3. The wires yi are drawn through holes in insulating plates 10 which are screwed to the bars 9. Each plate l0 carries a bundle of wires comprising ten lines each consisting of three wires, viz the two speaking line branches and a testwire.

The three wires of each line form CII CII

a horizontal layer of wires. The vertical wires 5 are similarly drawn through holes in insulating plates 11 screwed to the horizontal bars 8. Each selector mechanism has one incoming line consisting of three wires 5.

The connections between the incoming and outgoing lines are established by means oit Contact arms 12 arranged at the points of intersection et the dil'lerent lines and which con-siste ot elastic metal strips, which are soldered or otherwise connected to t-he wires F They are arranged so as to extend horizontally .Jetween the horizontal layers of wires 4, so that the ends oi' the contact arms will be l right above the corresponding wires f. tach set et three contact arms is arranged to be operated trein the selector mechanism through the medium of a thin plate 13 ot insulating material placed on the contact arms and adapted to be retained in position by the passing through holes in the plate. Said plate is normally kept in a raised horiposition by the contact arms 12. 1nscrted in the front edge ot said plate t-here r )ce olf metal 14 serving as an actuating pon 'for the selector' mechanism as will be described hereinafter.

'll he selector mechanism comprises a. number ot si iitching members 15. ln the example shown there are ten such members, which consist of sleeves thrust on a vertical shaft 1G and provided with Contact actuating members sisting of radial pins 1T arranged along a helical line. By rotating the sleeve said pins can be brought successively in operating position to actuate the metal pieces 14 on ti plates 3, so that the different groups of contact springs 12 are successively broughtin contact with the appertaining wires 4. The sleeves 15 are mounted in journals 18 secured to the lett hand side of a plate 19, which forms the trame in which the selector' mechanism mounted. 1n the example shown each selector mechanism is assumed to establish connection between one incoming line and one luuidred outgoing lines, the latter being arranged in tcn grcaips each containing ten lines. Thus, cach line group has allot-ted to it a separate switching sleeve 15. 1n order to bo able to establish connection in any line groiug wanted, the switching sleeves 15 are arranged to be coupled mechanically in and out otf connection with the shaft 1G by a vertical movement of the latter. The coupling is eli'eeted by means of pins 2O provided on the shatt, said pins being adapted, upon the sh:V being raised, to enter notches 21 in rings which are fastened inside the sleeves to their upper ends. The selecting of the differentswitching sleeves is ellected by means ot a step-wise uertical movement of the shaft 16 Jfrom its normal position. By raising the shaft one step lthe lirst i. e. the lowermost sleeve 15 is'coupled to the shaft 16 by the louermost pin 2() entering the notch 21 in said sleeve. 1i' connection is wanted with a line in the first group, the shaft 16 is then rotated stepwise the sleeve 15 being carried round by the pin 20. The lowermostpin 17 on said sleeve will then press against the metal piece 14 ot the lowermost plate 13, which therefore will press the ap iertaining group et contact arms 12 into contact with the corresponding wires 4. Figures 1 and 3 show the position ot' the mechanism aifter the sleeve 15 thus been rotated for one step in the direction ot the arrow shown in Figure 3. If the shaft 16 is rotated for another step, the .first group oi Contact arms is released and is caused by the elasticity of the Contact arms to resume its normal position, the second group ci Contact arms being instead actuated by the second pin 17 on the sleeve 1n this way evidently any wanted group et Contact arms may be selected and operated. During the switching operation in one line group the switching sleeves 15 oit' all the other Y liuc groups are inoperative, as the appertaining coupling pins 20 are not then in engagement, .'ith the corresponding sleeves. It the shatt is at first raised two steps, the second itching sl eve 15 will be coupled to the att 1G by the appertaining pin 2O entering n' ito engagement with the notch 21 ol the second sleeve. The coupling pin 2O ot the lirst switching sleeve will then be located above this sleeve and the following rotation of the shatt 16 will therefore only `rause the second Yitching sleeve to be rotated. Similarly the third, fourth etc. switching sleeves can be coupled to the shaft 16 by lifting the shaft three, tour etc. steps. After the end of the conversation the shaft 16 and the sleeve 15 are restored to normal position by a iurther rotation ot' the shatt 16 in the same direction, until it reaches its normal position, in which the pins Q() are all right below the notches 21 et the. appertaining sleeves.

The motion mechaz'iism consists o1 a litting electro-magnet and a rotary magnet 24 with appertaining driving pawls and 2G respectively operating on teeth 2T and 28 respectively on the lower end ot the shaft 16. During the operation ot the electromagnet 23 the shaft is maintained in a raised position of the pawl 29, which together with the pawl 25 may be brought out ot' engagement with the teeth 27 by means ot a restoring electro-magnet 30. The magnets 3, 24 and 30 are mounted together with the shaft 16 and the appertaining switching sleeves 1l on the left hand side of the appertainiug trame 19, which thus carries the whole selector mechanism. The frame 19 is secured to the transversal bars 2, 3 by means of screws 31, 32 in such a manner that it can be easily detached by loosening said screws. The mounting of the frame in its position is facilitated by its lowermost edge being guided in a slot 33 provided in a base plate 34 screwed to the lower bar 3. A transversal bar 35 serves as a support for the frame while being inserted in its place.

The setting movements of the selectors may also be continuous in which case the shaft 16 is arranged to be driven from ro tating shafts or the like according to methods well known in the automatic telephony.

In a selector of the kind above described the present invention may be applied in dif'- ferent ways. For instance, the switching members 15 belonging to different selectors but operating` in the same line group may be displaced relatively to each other so that, while being rotated, they will select and operate the different sets of contacts in a different order of sequence. The arrangement may for instance be such that one selector, when started to select an idle line, may first operate the lowerrnost setof contacts and then the other sets of contacts in succession in the manner above described, whereas the other selectors may first operate the second, the third etc. set of contacts and then the remaining sets of contacts in succession. A similar result may be obtained by providing the different selectors with different switching sleeves for instance of the kind shown in Figures 4 to 9, which differ from the switching sleeves shown in Figures 1 to 3 by the arrangement of the contact operating pins 17. In a group of three selectors for instance the first selector may have a switching` sleeve of the kind shown in Figures 4 and 5, the second selector a switching sleeve according to Figures 6 and 7 and the third selector a switching sleeve according to Figures 8 and 9. In Figures 4 and 5 the arrangement of the pins 17 is such that, when rotating the sleeve from its initial position in the direction of the arrow in Figure 5, t-he different sets of contacts are operated in succession from above and downwards. In the arrangement of the pins 17 according to Figures 6 and 7 the different sets of contacts will be operated in succession from below and upwards. In the arrangement according to Figures S and 9, on the other hand. the sixth set of contacts will be first operated and then in succession the 7th, 8th, 9th, 10th, 5th, 4th, 3rd, 2nd and 1st sets of contacts. By varying the arrangement of the pins 17 on the switching sleeves at the different selectors in this way the trafiic may be distributed over the junction lines of a group.

In the arrangement above described it has been assumed that the switching sleeves have a fixed normal position to which they are restored after the end of the conversation. rfhe arrangement may, however, easily be modified so that the restoring of the switching sleeves may be dispensed with. For this purpose the rings 22 inserted in the ends of the switchingsleeves may be provided with ten notches 21 corresponding to the ten different setting positions of the sleeve. It is evident that in such an arrangement the switching sleeve may be left standing in any setting position even after the end of the conversation if instead thereof the telephone connection is broken at another Joint of the connection. It will therefore on y be necessary to restore the shaft 16 in a vertical direction and the pins 2O will then pass freely through the notches 21 in the rings 22, I'Vhen the selector is taken into engagement the next time, the shaft 16 is first raised in the samemanner as before so as to be coupled with the switching sleeve wanted. The latter may then be in any angular position. Thereupon the rotation of the switching sleeves will take place in the manner above described. In this arrangement the different switching sleeves 15 of the different selectors may be identical in respect of the arrangement of the pins 17 as the desired distribution of the traflic will be attained by the different switching sleeves being started from different initial positions.

Figures 10 and 11 illustrate a group-selector having movable contact arms and the contact field of which consists of bare wires 36 extending perpendicularly to the shafts 37 of the selectors and forming a single vertical layer of wires. Secured to the selector shaft 37 are a number of cylindrical sleeves 38 of insulating material carrying contact pins 39 arranged helically on the sleeve. By rotating the shaft said contact pins may be brought successively in contact with the line wires 36, whereby any wanted line may be selected similarly as above described. The contact pins 39 are electrically connected together and connected to contact rings 40, 41, 42 at one end of the sleeve, wipers 43, 44, 45 being provided for connecting said rings with the corresponding wires of a junction line 46. If the shaft 34 is provided with ten such sleeves, there will be ten junction lines which are connected to the fixed contacts of an auxiliary selector 47 by means of which any junction line may be selected in any wanted group of outgoing lines 46. This selector need not have any fined normal position. After the end of the conversation it may thus be left standing in the position in which it has been previously set. Vhen taken into engagement the wanted group is first selected by means of the auxiliary selector 47 and then a disengaged line in this group is searched for by rotating the shaft 37 for instance by means of an electro-magnet 48, a driving pawl 49 and the ratchet wheel 50 on the shaft 37. During the rotation all sleeves 38 partake in the rotary movement of the shaft but only one of them is electrically operative.

I claim:

1. In an automatic telephone system the combination of a plurality of group selectors, a plurality of numerical groups of outgoing lOO llO

lines accessible in common to said group-selectors, incoming lines of said group-selectors connected to fixed sets of contacts of the contact fields of the group-selectors, a plurality of switching members in each group-selector corresponding to the dierent groups of lines and, each provided with a plurality of contact operating members for mechanically actuating the sets of cont-acts of the appertaining group in succession, the switching members of different group-selectors pertaining to the sa-me numerical group being arranged to actuate the sets oYccntacts in a different order of sequence While being started each time from a predetermined position.

2. A group selector as set forth in claim l in Which the switching members belonging to the same line group have predetermined normal positions to which they are restored after disconnect-ion of the telephone connection.

3. A group selector as set forth in claim l in which the switch members are rotatably arranged and driven on a. common shaft in the same direction. y

In testimony whereof I affix my signature.

DAVID LAURENTIUS LrENZitN. 

